The craft is carrying around 1,200 pounds of water, food, clothing and other supplies for the station's six astronauts. Photograph: NASA/AP

Astronauts at the International Space Station captured the Dragon capsule on Friday, in small step for robotic arms but a giant leap for privately funded interstellar services.

"It looks like we've got us a dragon by the tail," Nasa's Don Pettit told mission control in Houston at 9.56am ET.

It is the first American craft to dock at the station since the US grounded its shuttle programme, marking a shift towards outsourcing space expeditions to the private sector.

The Dragon cargo capsule was built by Space Exploration Technologies (SpaceX), the brainchild of PayPal billionaire Elon Musk. It blasted off into space on Tuesday.

The craft is carrying around 1,200 pounds of water, food, clothing and other supplies for the station's six astronauts, and it is due to remain docked for about a week before being released. Before heading back, Dragon will be stocked up with equipment from the International Space Station.

Unlike other cargo vessels which burn up on re-entry, the SpaceX craft is expected to survive the trip back to Earth. It is due to splash down off the coast of California on Thursday.

The task of capturing the capsule appears to have gone smoothly. Pettit and fellow astronaut Andre Kuipers used a 58ft robotic crane to grab Dragon and attach it to the space station.

SpaceX is helping share the burden of resupplying the international station with crafts from Russia, Europe and Japan. It forms part of President Barack Obama's space strategy of handing over orbital flights to the private sector, freeing a slimmed-down Nasa to concentrate on the farther reaches of the cosmos and unmanned missions to Mars.

US authorities have also expressed a desire to buy commercial flights for its astronauts, breaking Russia's monopoly on flying crews to the station. SpaceX has said it hopes to upgrade its services to manned flights in the future.